The publication “A Small, Light Radar Sensor and Control Unit for Adaptive Cruise Control” by Olbrich, Beez, Lucas, Mayer and Winter, SAE-Paper 980607, presented at the SAE International Congress and Exposition, Detroit, 23, Feb. 23-26, 1998, describes a motor vehicle radar sensor, which detects objects in the travel path of a vehicle and controls the vehicle deceleration devices or vehicle acceleration devices as a function of the detected objects. If the radar sensor detects no object or only detects objects which are not identified as vehicles traveling ahead, the vehicle velocity is regulated as constant velocity regulation. However, if the radar sensor detects objects which are identifiable as vehicles traveling ahead, the vehicle velocity is regulated as constant distance regulation. For this purpose, a three-beam microwave transceiver is used, which emits a frequency-modulated continuous-wave signal and receives reflected partial waves.
German Patent Application No. DE 100 11 263 A1 describes an object detection system, which is provided for vehicles in particular, in which the object detection system has a plurality of object detectors and/or operating modes for different detection ranges and/or detection areas. A radar sensor which has a relatively great detection range and a relatively small angular detection area in a first operating mode and a comparatively small detection range and increased angular detection area in a second operating mode is preferably used as the object detector. This system uses different surroundings sensing devices, each surroundings sensing system covering a different detection area.
In the book “Handbook of Computer Vision and Applications,” Academic Press, Boston, 2000 by Jähne, Hauβecker and Geiβler, in the section “Motion” on pages 307 through 392, methods for processing moving images are described, in particular methods for determining and processing the “optical flow.”